Modelling and Simulation of General Path Centrifugal Pendulum Vibration Absorbers 2015-24-2387
The aim of this paper is the study of the Centrifugal Pendulum Vibration Absorber (CPVA) dynamic behavior, with the background of improved vibration isolation and damping quality through a wide range of operating speeds.
The CPVAs are passive devices, which are used in rotating machinery to reduce the torsional vibration without decreasing performance. After a first use of these damping systems in the field of aeronautics, nowadays CPVAs are employed also in railway and automotive applications.
In principle, the CPVA is a mass, mounted on a rotor, which moves along a defined path relative to the rotor itself, driven by centrifugal effects and by the rotor's torsional vibrations.
The advantage that such absorbers provide is the capability to counteract torsional vibrations arising with frequencies proportional to the mean operating speed. This is in particular the case with Internal Combustion Engines (ICE) where the induced vibrations are caused by the combustions process.
The above-mentioned feature is obtained thanks to the tuning of the absorber on the specific ICE vibration order, obtained by means of its geometric characteristics.
The main goal of this work is to model and simulate different types of CPVAs, where simple vibration models can be implemented for first investigations. Special attention has been given to CPVAs modelled with circular, cycloidal and epicycloidal paths, using a general-path equation system approach. The CPVA unit performance has been analyzed by means of an nth order sine-signal torque.
In this simulation environment, the paper aims to highlight the capabilities of absorbing vibrations of CVPAs, emphasizing the configurations with cycloidal and epicycloidal paths where the vibrations of the designated order can be reduced to a level very close to zero, for a major part of the ICE speed range.
Furthermore the present work provides a simulation approach as basis for CPVA parameters optimization.